Obesity is a chronic , self-aggravating metabolic condition characterized by excessive accumulation of body fat , which can lead to several comorbidities , including cardiovascular disease, type 2 diabetes, hypertension, dyslipidemia, some forms of cancer, and respiratory disorders. In a context where the prevention and management of non-communicable diseases have become global health priorities, understanding the epidemiological dynamics of obesity in Italy is essential to develop effective intervention strategies.
Epidemiology of obesity in Italy
Obesity is a public health problem of global importance, and Italy is no exception : we can speak of a real obesity epidemic in the Western world . Over the last thirty years, the incidence of obesity in our country has shown a worrying trend, with a significant increase in prevalence rates among adults and children.
Overweight and obesity in adults
The Italian Obesity Barometer Report (IOBR) provides a detailed snapshot of the evolution of obesity in Italy, highlighting trends and the impact of this condition on public health. The 2022 data reveal an alarming picture: the prevalence of obesity among Italian adults is constantly increasing. Currently, 12 % of the adult population suffers from obesity (with a body mass index – BMI ≥ 30), while 34.2 % is overweight (BMI between 25 and 29.9). This means that over 46 % of Italian adults have a body weight above the norm, for a total of more than 25 million people. The lowest prevalence rates of excess weight are found among young women aged 18-24 (13.7% vs. 24.5% of their male peers), while the highest rates are found among men aged 65-74 (69.2% vs. 52.8% of their female peers).
Gender differences are marked , with men at a disadvantage compared to women at all ages. In the adult population, obesity affects 12.9% of men and 11.1% of women overall. At 18-24 years of age, the prevalence is lower and very similar between men and women (4.4% and 4.2% respectively in 2021), but quadruples in the 65-74 age group, reaching 18.8% among men and 16.5% among their peers.
Overweight and obesity among children and adolescents
The “ Okkio alla salute” survey conducted by the Istituto Superiore di Sanità , which has been monitoring the eating habits and body weight of Italian children and adolescents since 2007, has highlighted worrying data even among the youngest, with childhood obesity rates hovering around 10% and now stabilized for about a decade. The situation is particularly alarming in the southern regions, where obesity rates are higher than in the northern regions, even if the spread of the phenomenon is transversal to all Italian geographical areas. Childhood obesity in Italy is a growing and worrying phenomenon. According to the “ Okkio alla salute 2023” report, approximately 19% of Italian children between the ages of 6 and 11 are overweight, and 10% are obese. The prevalence of obesity is higher in the southern regions, where factors such as eating habits, less accessibility to healthy lifestyles and little physical activity seem to play a decisive role. Another study, conducted by the ISS, observed how obesity in children is closely linked to socioeconomic variables, with low-income families showing greater difficulty in adopting healthy lifestyles. In Campania, in 2023, an overall rate of overweight and obesity among children was recorded above 43%, among the highest in the entire world.
Geographical differences
Geographically, the regions of Southern Italy show the highest rates of obesity. The minimum value of excess weight is recorded in Liguria for both men (47.2%) and women (30.3%), while the maximum value for men is found in Campania (62.6%) and for women in Basilicata (47.1%).
This gap reflects socioeconomic and cultural differences, with the South also recording higher rates of overweight (over 40% in some regions). Obesity is, in fact, strongly correlated with socioeconomic factors. Adults with a low level of education or from families with modest income tend to have a higher prevalence of obesity, due to limited access to healthy foods and opportunities for physical activity, as well as, as highlighted by some studies by CREA, a lower knowledge of the basic principles of nutrition.
Impact on the system
The implications for public health are significant. Obesity is associated with numerous comorbidities : approximately 70% of obese adults have at least one related chronic condition, such as type 2 diabetes, hypertension, dyslipidemia and cardiovascular disease. The risk of developing these conditions is more than doubled in obese people compared to those of normal weight. The WHO estimates that obesity contributes to 7-8% of all premature deaths in Europe.
The increase in the incidence of chronic diseases has a significant impact also on the national health system, with direct costs estimated between 6.8 and 7.6 billion euros per year, including the treatment of comorbidities and hospital expenses. In addition, obesity also burdens the system with indirect costs related to lost productivity and work.
Ultimately, obesity represents one of the major challenges for public health in Italy. IOBR data highlight the urgency of multidisciplinary interventions to address this epidemic. A joint effort is needed to promote a healthy lifestyle, improve nutrition education and ensure access to physical activity opportunities, especially in the regions and social groups most affected. Only with integrated strategies will it be possible to reverse the growing trend and mitigate the long-term effects of obesity on the health and economy of the country. The territorial nutritionist , appropriately trained, can become a central figure to convey correct messages to the population in terms of prevention of excess weight and obesity-related diseases.
Factors contributing to the rise of obesity
There are many factors that contribute to the increase in obesity rates in Italy, including changes in lifestyle, a poorly balanced diet that is less and less Mediterranean and more Westernized, a sedentary lifestyle and social and economic inequalities. The change in eating habits, with an increasing use of foods with a high energy concentration , rich in sugars and fats, is one of the main drivers of the obesity epidemic. The study “ Epic ” ( European Prospectus Investigation into Cancer and Nutrition ), conducted in several European countries, has shown how a diet rich in processed foods and poor in fruit, vegetables and fiber is related to a greater risk of developing obesity and chronic diseases. The increase in consumption of sugary drinks, packaged snacks and ultra-processed foods is now a consolidated trend, especially among children and young adults. Inadequate breakfasts, overly abundant snacks and high consumption of drinks and juices rich in sugar have contributed to worsening the situation.
In parallel, sedentary lifestyle has proven to be another crucial factor. An increase in physical inactivity has been recorded , also linked to urbanization and the spread of technological devices, which have reduced the level of daily physical activity. Data from the World Health Organization (WHO) suggest that approximately 30% of Italian adults do not meet physical activity recommendations, with a clear prevalence of this phenomenon among women and the elderly.
Nutritional and nutraceutical intervention.
Overweight and obesity are generally caused by an imbalance between caloric intake and energy expenditure, but numerous biological, psychological and environmental factors influence eating behavior and weight management. Among the most promising strategies to combat this condition, a significant role is played by dietary modulation, in particular through the supplementation of prebiotic non-viscous soluble fibers.
In this context, dietary fibers, especially non-viscous soluble ones such as resistant dextrins, can have a crucial impact both in the treatment and prevention of overweight and obesity. They not only improve intestinal function, but are also able to modulate the intestinal microbiota and, through the production of short-chain fatty acids ( SCFAs ), influence the sense of hunger and satiety.
The Role of Prebiotic Soluble Fibers in Body Weight Regulation
Fibers and their impact on the gut microbiota
Dietary fibers are mainly represented by complex carbohydrates that cannot be digested by human enzymes. Some of them have characteristics of fermentability by the intestinal microbiota. There are different types of fibers, including soluble fibers, which dissolve in water and can form viscous or non-viscous gels , and insoluble fibers, which do not dissolve and increase the volume of feces. Soluble fibers, in particular those with prebiotic characteristics, which act as nourishment for the bacteria that make up the microbiota, are known for their ability to modulate the composition and activity of the intestinal microbiota itself , stimulating the growth of beneficial bacteria such as Bifidobacteria and Lactobacilli . This microbiotic modulation has direct effects on intestinal functionality and energy-metabolic regulation.
Non-viscous soluble fibers, such as resistant dextrins, are a special type of fiber that, while soluble in water, do not form viscous gels and are resistant to digestion in the upper intestine. These fibers are fermented by gut bacteria in the colon, producing short-chain fatty acids ( SCFAs ) such as butyric acid, acetic acid, and propionic acid. SCFAs have a significant effect on metabolism and gut health, influencing weight control and appetite regulation.
SCFAs production : effect on metabolism and satiety
SCFAs are the main products of soluble fiber fermentation by the intestinal microbiota. These fatty acids play a fundamental role in modulating energy metabolism and feeding behavior. When fiber is fermented in the colon, small amounts of SCFAs are produced , which are then absorbed by the intestinal mucosa and transported into the blood, where they exert numerous physiological effects. Among the main effects of SCFAs is their ability to influence the production of intestinal hormones, including Glucagon- like peptide -1 ( GLP-1 ) .
GLP-1 is a gut hormone that plays a crucial role in regulating energy metabolism by stimulating insulin secretion and inhibiting glucagon secretion , with the aim of reducing blood glucose levels. Additionally, GLP-1 is involved in the regulation of central satiety, a process that occurs in the brain and signals the body when it is time to stop eating. SCFAs , produced by the fermentation of non-viscous soluble fibers, have been shown to stimulate GLP-1 secretion, helping to improve appetite control and promote a long-lasting satiety effect.
Central satiety vs. s at iation : Key concepts in weight management
It is important to distinguish between satiation (fullness) and satiety (central satiety), two concepts that, although related, refer to different physiological mechanisms. Satiation refers to the feeling of fullness that develops during eating, in response to the stretching of the stomach and intestinal distension, which send signals to the brain to stop food intake. This phenomenon is related to eating behavior during the meal.
Satiety , on the other hand, refers to the feeling of satiety that persists after finishing a meal, or the duration of the feeling of fullness that prevents the desire to eat. Central satiety is regulated by a series of hormonal and nervous signals that come from the intestine, and here SCFAs and GLP-1 play a fundamental role. The activation of these hormonal pathways is crucial for weight control, as it promotes the feeling of satiety in the long term, reducing the sensation of hunger and the risk of overeating.
Non-viscous soluble fibers are found primarily in whole grains and legumes, but can also be industrially produced as dietary supplements. When consumed, resistant dextrins ferment in the colon and produce SCFAs that activate receptors in gut neurons and stimulate the production of GLP-1, which, as mentioned, has a powerful effect in reducing appetite and promoting satiety.
Effects of Fiber on Satiety: Impact on Digestive Physiology
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Cephalic phase of digestion
It is the phase that precedes the arrival of food in the stomach , it is mediated by exposure to stimuli such as thinking about food, seeing, smelling food and chewing it. The presence of insoluble fibers, By increasing chewing times, it can contribute to satiety .
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Gastric phase of digestion, gastric volume and retention time of food/chyme in the digestive tract
The ingestion of the food causes gastric distension with the sending, via the vagus nerve, of satiety signals to the system central nervous system. The duration of distension is influenced by the rate of emptying gastric. Soluble fibres, especially viscous ones, keep food in the stomach longer and slow down its rate of digestion. emptying also acting through mechanisms downstream of the gastrointestinal tract.
In fact, in the intestine , the increase in chyme viscosity induced by fibres, with a dose-dependent action, reduces the interaction between digestive enzymes and substrates with slowing down of digestion and absorption. In This way the arrival of macronutrients at the distal ileum is prolonged with stimulation enteroendocrine cells of the ileal mucosa to produce peptide hormones ( incretins ) such as GLP-1 and Peptide YY (PYY).
These reduce the mobility of the stomach and slow down its emptying, prolonging satiety, understood as satiation. and, at the same time, optimize the balance between digestion and absorption.
These mechanisms are called ileal brake or ileal brake of gastric motility. But GLP-1 and PYY , moreover , induce satiety also at the hypothalamic level, due to the mechanism described previously, since the synthesis of GLP1 and PYY is also induced by short-chain fatty acids ( SCFAs ) produced by the microbiota following fermentation, especially of non-viscous soluble fibres.
The Nutritionist in the approach to overweight and obesity
The Nutritionist, in addition to developing personalized diets, always starting from a complete evaluation of the nutritional status along the three axes of blood chemistry, testing and anthropometry, preferably performing a vector bioimpedance analysis and taking into account any diagnoses formulated by the doctor, can therefore also make use of nutraceutical supplements such as functional fiber. Integration with soluble non-viscous prebiotic fibers, such as resistant dextrins , is a useful strategy that the Nutritionist can adopt to optimize body weight management. This integration is particularly effective in patients suffering from obesity, since it improves not only intestinal health but also weight control, stimulating the production of SCFAs which, as we have seen, promote central satiety, without forgetting that the daily requirement of fiber by Italians is rarely met.
Conclusions
In summary, non-viscous soluble prebiotic fibers, such as resistant dextrins, have an important role in the prevention and treatment of overweight and obesity. Their ability to modulate the intestinal microbiota and stimulate the production of SCFAs is essential for regulating energy metabolism and feeding behavior. SCFAs , in turn, promote the production of GLP-1, a hormone that reduces appetite and promotes central satiety, thus contributing to body weight control.
The integration of these fibers in diet represents an effective strategy for patients struggling with overweight and obesity, especially in a context where weight management is based not only on caloric intake, but also on hormonal and microbiota regulation. Such an integrated and evolved approach not only improves weight control, but also promotes a better quality of life for patients.
